Regarding the "Pro Audio" speakers he released, I had to ask this question 2x and he never even responded, but several weeks after my initial inquiry he did finally change the T/S specs for them. You can see by the dates below that on 10/24 he posted specs to the website and as of 11/15 he still hadn't changed them.... And those T/S parameters make absolutely no sense at all. The variances are large enough to not even be close to considered errors due to averaging over a production run. They're just wrong. The PAX-6.5, for example. Re of 4ohms? I've never seen a speaker with an Re of 4ohms....nominal impedance, yes. But not Re. I'm going to presume it's 4ohm nominal and it's Re is somewhere in the 3.X range? Second, a Qes of 1.758 and a Qts of .412 ? Even with nothing but a rudimentary understanding of T/S we can tell those numbers don't match up. Qes is the main determinant of Qts....those two numbers should be much closer. Qts should be more in the vicinity of 1.4 You list No as .19% and SPL 89.8db. Based on the listed Fs, Qes and Vas the No calculates out to be 1.28% and SPL 93db. A No of .19% would equate to a sensitivity of 84.8db, not 89.8db. So, in short, none of those numbers match up. Your units for compliance are wrong, or your decimal is in the wrong spot. I'm assuming it's really .090742 mm/N Based on the listed Vas and Cms, the Sd would be around 446cm^2, which is not much smaller than a 12" driver and obviously not correct. Based on Mms and Cms, Fs should be 126hz, not 97hz. That's not an all encompassing list, but a brief summary. In short.....those parameters are physically impossible and make no sense together whatsoever. After he corrected the specs (several weeks after my initial inquiry), I don't know if they are accurate but atleast they are reasonably mathematically consistent. Here are my problems with the drivers: Honest opinion? They are turds. I don't see a single circumstance in which there isn't much better options available. Here's the problem, they wanted something they could call "pro audio" and looked "pro audio" by appearance but didn't want the lack of midbass problem pro audio drivers suffer in most car audio style installations (unfortunately they failed miserably on both counts). So they used pro audio style soft parts with a low mass and in this case looks like slightly less compliant suspension so they have the "pro audio" look and also the high Fs (actually a higher Fs than a lot of true pro audio drivers). But they then tried to compensate for the lack of midbass output in most pro audio drivers by raising the Q....but they went too far and ended up with an extremely weak and underdamped motor. The downside to this is that the weak motor killed the efficiency and gave the driver way too high of a Q. The result is a driver with a really high Fs, average sensitivity and almost unusably high Qts. So it's going to have a giant peak early in the midbass followed by a steep roll off. And because the driver is highly resonant you are not going to be able to get tight, articulate midbass out of the driver.....it's going to be exaggerated and muddy, and it's still not going to have the low frequency extension of a normal driver. This driver is basically off the shelf a driver stuffed in WAY TOO SMALL of an enclosure; think about what happens to a subwoofer when you shove it in way too small of a sealed enclosure, and that is equivalently what this thing is even when it's IB in your door. DO NOT use them in an enclosure or sealed kickpanels....simply not going to work. If you were after a true pro audio driver, this isn't it. The weak motor killed the efficiency, it's really not much more efficient than a standard driver. So if you want pro audio efficiency, you will need to stick with the traditional pro audio offerings and this driver doesn't fit in that category. On the other hand, if you weren't after a pro audio driver I still don't see a use for this driver as a "normal" driver is going to have nearly the same efficiency and without such ridiculous parameters....they'll have a lower Fs, much lower Q and as a result won't have the over-exaggerated midbass response and huge peak with an early roll off of this driver. So if you weren't after a pro driver, there are still much better options than these. As such, I don't see any real use for these drivers as no matter which way you want to go, there are much better options available. Driver design is all about trade-offs and which set of trade-offs fit a particular goal. Unfortunately the designers of this driver chose absolutely ridiculous trade-offs and essentially made a driver that doesn't fit well in any category and is easily bested by a large number of drivers no matter the performance goals of the user. I know certain people aren't going to believe this: But there is truly no brand-bias in my comments here. This is strictly looking at the T/S parameters, I'd say exactly the same thing no matter what name was on the dust cap. He also had to go back and change the specs he released on the bullet tweeters after he released them and we questioned him on them, though he didn't actually answer any of our questions he just went back and changed some of the specs. First sensible post wrt to allegations. Other guys here sound like keyboard thugs.